I have a doubt about Google Cloud Platform…

I did an ASP.NET deployment via Google Cloud which created a VM instance.

When I connect to the VM via RDP I notice that the VM has SQL server installed.

Can I use that SQL server for my hosted website on the same VM or do I need to order a separate SQL database via Google Cloud SQL?

Some explanation on why I can or can’t use the SQL server on my VM would be very helpful as so far I did not succeed to find back anything about this in the documentation.
And what are the pros & cons if it can be used compared to Cloud SQL?

Thx
Frederik